Perfect Pool Bottom Kit Stops Anything From Puncturing Your Liner - Including Nutgrass! If You Have Problems With Nutgrass, This Is The Solution For Your Above-Ground Liner. Perfect Pool Bottom Is An Entire Kit Designed To Totally Protect Your New Liner And Add Years Of Life. The Heart Of This Liner Kit Is Perfect Bottom Hard, Flat Polymer That Is Placed Under Your Pool To Form A Smooth Bottom And Protect Your Liner. Nothing Can Get Through Perfect Pool Bottom - Not Roots, Stones, Glass Or Even Nutgrass! With Perfect Pool Bottom Even Footprints Are Eliminated. Also Included In The Kit Is Pool Cove Which Is Used Around The Perimeter Of The Inside Wall Of Your Pool To Protect Your Liner. Pool Cove Eliminates Excessive Liner Stretch To Prolong Your Liner’S Life. The Perfect Pool Bottom Kit Is Easy To Install. If You Are Looking To Prevent Nutgrass Then This Kit Is For You!